Scalable Newton-Krylov Solver for Very Large Power Flow Problems

The power flow problem is generally solved by the Newton-Raphson method with a sparse direct solver for the linear system of equations in each iteration. In this paper, alternatives based on iterative linear solvers are presented that are faster and scale much better in the problem size, making them ready for the ever-growing power systems of the future. For the largest test problem, with around one million busses, the presented alternative is over 120 times faster than using a direct solver.